The tilt sensor well and the battery well are waterlogged again after a rain fall.
The aerial base grommet is new and there's no sign of water or moisture around there.
The third brake light is dry and the boot wiring is dry.
I've looked at all the seems and they are dry.
The boot carpet is dry
Any suggestions because I can't figure it out.

The the most probable thing is the seal of the roof against the body. Remove the carpets and pour water over the rear window. My bet is that you will see water dripping inside the boot. The fix is to partially open the roof and seal the whole length of the seal with black Super7.
(The only other thing I can think of is the seal around one of your rear brake lights clusters.)

I've just found out that the rear window n/s is leaking on the zip seam ,it drips onto the mat behind the passenger's seat then finds it's way into the boot , yours might the same
peterz3
just as well I'm getting a new soft top fitted next month

I'm using a place near Stoke as that's just up the road from where I live new top is about £650 having it done in august
I had thought of the other place down near Croydon but that's a 3-5 hr trip each way with fuel wear and tear toll fee etc
peterz3

Do you park on a hill facing uphill? If so heavy rainfall will overwhelm the seal geometry and will find its way into the boot. There is no fix.....just park facing downhill and problem solved. On the flat or small slopes no problem......steep slope equals very wet boot.

one thing I've found out is when I had the new soft top fitted today there is a U shaped gutter just under where the roof is fixed so if the seal leaks the water is taken to just over the shock top mount the through the wheel archs, I don't know if this is fitted to all z3's or just the later models, if you pull the rear shelf carpet back you can see if yours has one
peterz3